Process and agent for breaking petroleum emulsions



Patent ed Mar. 25, 1943 PROCESS AND AGENT FOR BREAKING PETROLEUM EMULSIONS Richard A; Salathiel, Houston, Tex., assignor to Standard Oil Development Company, a corporation of Delaware.

No Drawing. Original application October 19, 1938, Serial No. 235,781. Divided and this an plicationDecember 19, 1939, Serial No. 309,957

6 Claims.

comprise fine droplets of naturally occurring waters or brines, dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion. They are obtained from producing wells and from the bottom of oil storage tanks, and are commonly referred to as cut oil, roily oil, emulsified oil, and bottom settling's. 1

The object of the present invention is to provide a novel and inexpensive process for separating emulsions of the character referred to into their component parts of oil and water or brine.

Briefly described, the present process consists in subjecting a petroleum emulsion of the waterin-oiltype to the action of a treating agent or demulsifying agent of the kind hereinafter described, thereby causing the emulsion to'break down and separate into its component parts of oil and water or brine, when the emulsion is permitted to remain in a quiescent state after treatment, or is subjected to other equivalent separatory procedures. 4

The treating agents used in this process consist of derivatives of organic, preferably aliphatic, unsaturated carbonyl compounds obtained by the condensation therewith of resin acids or resin acid bodies.

As used herein the term resin acid is used to designate abietic acid and pimaric, copaivic, palabietic, and other acids derived from the oleoresinous exudates from various species of Co'- niferae which are either identical or isomeric with abietic acid or are changed to abietic acid or anisomer of abietic acid by heating. The term resin acid body is used to designate these acids or simple functional derivatives of these acids, such as salts, anhydrides and esters. Similarly, the term abietic acid body embraces salts, esters, and the anhydride of abietic acid.

Typical of the unsaturated organic carbonyl which may be employed are polycarboxylic unsaturated open chain acids, such as maleic acid and fumaric'acid, their anhydrides and the'corresponding aldehydes' and ketones, benzoquithrough their unsaturated linkages with polycarbox ylic unsaturated-open chain acids and. derivatives thereof in which the unsaturated groupings are preserved.'- fMost commonly this reaction is carried out with maleic acid or maleic anhydride, or the corresponding fumaric compound. For the sake of simplicity, maleic anhydride and esters of maleic acid will be hereinafter referred to for illustrative purposes, but it is to be understood that in such references the whole group to which these substances belong is contemplated.

There are two steps in the preparation of these treating agents. The first is condensation by the well known Diels-Alderdiene reaction of a moi of the resin acid body with a mol of maleic anhydride to form a polybasic acid body. This condensation is usually carried out by heating the reactants. Reaction usually begins at about 100 C. but for a practical rate of reaction a temperature of the order of 200 to 250 C. should be employed. The upper limit on the condensation temperature is that temperature at which the reactants decompose, and other detrimental reactions take place.

The second step is the reaction of this polybasic acid body to form suitable derivatives. The

' polybasic acid body may be combined with water hydric alcohols and with ether-alcohols to yield materials that' economically demulsify some emulsions. The term ether-alcohol is used here- .in to designate an organic compound characterized by the presence of both alcoholic hydroxyl and ,etheric oxygen,- (--O-), groups. Among suitable alcohols for this purpose may be mentioned mono-methyl, mono-ethyl, mono-propyl, mono-butyl, mono-amyl, etc., ethers of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, etc., propylene glycol, butylene glycol and other glycols; di-methyl, di-ethyl, dipropyl, di-butyl, etc. ethers of glycerol, and other tri-hydric alcohols; 'mono-alkyl ethers of tri 'methylene glycol, tetra-methylene glycol, penta-methylene glycol, and the like. Also the polybasic acid bodies may be condensed with polyhydric alcohols to yield materials having excellent demulsifying powers. Typical of the polyhydric alcohols which may be employed are etthylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, butylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, glycerol, -butanetriol, pentanetriol, tetramethyl glycerol, pentaglycerol, erythritol, pentaglycerol.

pentaerythritol, ortho, meta, and para phth'alyl alcohols, mesicerin, etc.

Also suitable derivatives are formed by combining the reactions described above. Thus. mixed monohydric and polyhydric alcohol ester derivatives of the condensed polybasic acid body may be produced. Likewise, partially saponified complex ester derivatives of the resin acid bodymaleic anhydride condensation product may be highly eflicient demulsifying chemicals.

The order in which the reactions in the prepa ration of these derivatives are carried out is in most cases immaterial. A derivative of the condensed acid body may be prepared before or after condensation. For example, it is immaterial whether the mono-butyl ether of diethylene glycol is esterified with maleic acid and the resulting ester condensed with methyl abietate or the methyl abietate is first condensed with maleic anhydride and the resulting condensation product esterifled with the mono-butyl ether of diethylene glycol. It is the final product that it is desired to describe by the reactions set down. Reactions carried out in any other order to obtain these products must be regarded as equivalent.

The reagents preferred for use in practicing the process of the present invention are either the monohydric or the polyhydric alcohol ester derivativesof the acid resin obtained by condensing an abietic acid body with maleic anhydride.

Specific illustrations of products of the type hereinbefore generally described which are suitable for use in accordance with the present in vention are set forth below. It is to be understood that the present invention is not in any way restricted to the specific chemicals described in these examples or the proportions in which they are employed, as it will be readily apparent that equivalents of these specific chemicals and other proportions, as well as variations of the order and mode of combination may be employed without departing from the spirit of the present invention or the scope of the ap pended claims. In these examples proportions are given as parts by weight.

Example I Methyl abietate, 316 parts, and maleic anhydride, 98 parts, are condensed together by, heata ing at 230 C. for an hour. A small excess, say

290 parts, of diethylene glycol mono-butyl ether is added and the mixture refluxed in an apparatus fitted with a fractionating refiuii'column,

devised to remove the water as rapidly as DOS-7 sible as it is formed, by heating to about 220 to 250 C. until the reaction is complete, or for about four hours. The product is a highly viscous liquid readily soluble in most organic solvents.

Example 11 Example III Methyl abietate, 680. parts, and maleic anhydride, 214 parts, are condensed together by heating at 230 C. for an hour. Glycerol, 134 parts, is added and the mixture heated, under thorough stirring, at' 195 C. for an hour and then at 230 C. for an hour. This yields a fairly hard resinous material which dissolves suitably in aromatic solvent-isopropyl alcohol blends.

Example IV Example V Amyl abietate, 372 parts, and maleic anhydride, 98 parts, are heated together for two hours at 215 C. to efiect condensation. Glycerol, 91 parts, is added and the mixture heated at 225 C. for two hours to yield a hard resinous body which dissolves suitably in isopropyl alcoholaromatic solvent blends.

Example VI Methyl abietate, 316 parts, and maleic anhydride, 98 parts, are condensed together by heating at 230 C. for an hour. Ethylene glycol, 62 parts, is added and the mixture heated with eillcient stirring at 230 C. for two hours to yield a hard resin, solutions of which in inert solvents have excellent demulsifying properties. It dissolves suitably in aromatic solvent-isopropyl alcohol blends.

In practicing the process of the present invention the materials previously described need not be employed alone but may be employed in conjunction with other suitable demulsifiers such as water softeners, .modified fatty acids, oil soluble or water soluble petroleum sulfonic acids and various other well known demulsifiers for water-in-oil emulsions. The mixtures and proportions of the chemicals which yield the most economical treatment will vary with the various I emulsions to be treated. One may add any suitable inert solvent or solvents which would lower the viscosity of the product and so make it more adaptable for use.

In practicing the present invention, a treating agent or demulsifying agent of the kind above described may be brought into contact with the emulsion to be treated in any of the numerous ways now employed in the treatment of petroleum emulsions of the water-in-oil type with chemical demulsifying agents, such as, for example, by introducing the treating agent into the well in which the emulsion is produced, introducing the treating agent into a tank in which the emulsion is stored, or introducing the treating agent into a container that holds a sludge obtained from the bottom of an, oil storage tank. In some instances, it may be advisable to introduce the treating agent into a producing well in such a way that it will become mixed with water and oil that are emerging from the surrounding strata, before said water and oil enter the barrel of the well pump or the tubing up through which said water and oil flow to the surface of the ground. After treatment the emulsion is allowed to stand in a quiescent state, usually in a settling tank, at a temperature varying from atmospheric temperature to about 200 F., so as to permit the water or brine to separate from the oil, it being preferable to keep the temperature low enough so as to prevent the valuable constituents of the oil from volatilizing. If desired, the treated emulsion may be' acted upon by one or the other of various kinds of apparatus now used in the iperation of breaking petroleum emulsions, such as homogenizers, hay tanks, gun barrels, filters, :entrifuges, or electrical dehydrators.

The amount of treating agent on the anhydrous oasis that is required to break the emulsion may vary from approximately 1 part of the treating agent to 500 parts of emulsion up to 1 part of treating agent to 30,000 parts of emulsion depending upon the type or kind of emulsion being treated. In treating exceptionally refractory emulsions of the kind commonly referred to as tank bottoms or residual pit oils, the maximum ratio above referred to may be required, but in treating fresh emulsions, i. e., emulsions that will yield readily to the action of chemical demulsifying agents, the minimum ratio mentioned may frequently be satisfactory. For the average petroleum emulsion of the water-in-oil type a ratio of 1 part of treating agent to 10,000 parts of emulsion will usually be found to produce commercially satisfactory results.

It is, of course, understood that some experiment will be required in order to select the precise agent of the aforedescribed group which should be employed for any given emulsion and the quantity in which it is to be employed. As is well known, emulsions vary from well to well and from time to time in any given well, so that it is quite impossible to lay down any general rule which will be applicable to all emulsions which may be encountered. In order to give some indication, however, of the utility of the agents produced according to the present invention, in the treatment of emulsions, the following specific cases are given. The tests hereinafter described were carried out in laboratory glassware under conditions similar to those which generally exist in the field in treating petroleum emulsions:

A crude petroleum emulsion (from the Humble Gail #53 well on the John Gaillard lease in the Goose Creek, Texas, field) which contained 68% of salt water, was caused to separate into three layers in a few minutes at 125 F. by the addition of a small amount of solution containing four hundredths of one percent (based on the amount of emulsion treated) of material pre-' pared as described in Example II, mixing well and allowing to stand. The top layer contained practically all of the oil almost entirely free from water. The middle layer which was .quite thin compared to the other two layers contained mineral oil, water, and the added substance. The bottom layer contained practically all of the salt water free from oil.

Under the same conditions this emulsion remained practically unchanged for many hours if no chemical was added.

The same emulsion was caused to separate in a few minutes at 125 F. into two layers by the addition of a small amount of solution containing two hundredths .of one percent of material prepared as described in Example II and two hundredths of one percent of oil soluble salts of petroleum sulionic acids, (based on the amount 9f emulsion taken) mixing well and allowing to stand. The upper layer was composed of clear oil practically free of salt water and the lower layer was composed of salt water practically free of 011.

Even several times the amount of the oil soluble sodium salts of petroleum sulfonic acids which in the above case was added, if applied alone under the same conditions, has no appreciable efiect in breaking this emulsion.

The same emulsion .was caused to separate almost completely within 30 minutes at F. into two layers, the upper layer being oil, nearly free of salt water, and the lower layer being salt water, nearly free of oil, by adding a small amount of solution containing 1 part of material prepared as described in Example III to 5,000 parts of emulsion, mixing well, and allowing to stand.

This same emulsion was broken and caused to separate into layers of oil, practically free of salt' water, and of salt water, practically free of oil, within 30 minutes at 125 F. by adding a small.

amount of solution containing 1 part of material prepared as described in Example III and 1 part of oil soluble salts of petroleum sulf'onic acids to 10,000 parts of emulsion, mixing well and allowing to stand.

The present invention having been thus described, what is claimed as new and useful and is desired to be secured by Letters Patent is:

1. A process for breaking petroleum emulsion of the water-in-oil type' which comprises subjecting the emulsion to the action of a mixture containing a product obtained by condensing according to the Diels-Alder reaction a resin acid body with an organic unsaturated carbonyl compound operative in a Diels-Alder synthesis and an oil soluble sulphonated product derived from I petroleum oil.

2. A process for breaking petroleum emulsions of the water-in-oil type which comprises subjecting the emulsion to the action of a mixture containing a Dials-Alder condensation product of a resin acid body with a polycarboxylic unsaturated nated product derived from petroleum oil.

4. A demulsifying agent for petroleum emulsions of the water-in-oil type comprising a mixture containing a Diels-Alder condensation prodnot of a resin acid body and an organic unsaturated carbonyl compound operative in a Diels- Alder synthesis and an oil soluble sulphonated product derived from petroleum oil.

- 5. A demulsifying agent for petroleum emulsions of the water-in-oil type comprising a mixture containing a Diels-Alder condensation product of a resin acid body with a poly-carboxylic unsaturated open chain acid body operative in a Diels-Alder synthesis and an oil soluble sulphonated product derived from petroleum. oil.

6. A demulsifying agent for petroleum emulsions of the water-in-oil type comprising a mixture containing an ester of a Diels-Alder condensation product of a resin acid body with a polycarboxyllc unsaturated open chain acid body operative in a Diels-Alder synthesis and an oil soluble sulphonated product derived from petroleum oil.

RICHARD A. SALATHIEL. 

